GCR's (Gray Component Replacement) design is an important part in the process of generating ICC (International Color Consortium) profiles to be used for rendering high quality images. The designer pays special attention to the CMYK response everywhere in the gamut of the printer. Particularly some of the key colors (e.g., black in flesh tones and sky tones) need less black ink. These adjustments are stored as standard profiles (e.g., ICC profiles). In some cost-critical imaging applications, customers are interested in using black-only toner/ink when their images contain R=G=B pixels. For such applications, the image path should have a provision to transform the image RGB pixels to K only responses resulting in the generation of “K” only click charges. This approach is preferred by many customers to save the cost of color toner.
Solutions previously or currently offered include, for example: (i) print as grayscale option; (ii) color mode—grayscale; (iii) use of Pure Rendering Intent, and (iv) a search method that renders R=G=B pixels with K only. The grayscale printing uses a single R=G=B to K look-up table (LUT) designed for sRGB source space which is not optimized for image quality (IQ). Also, if the job in question requires this rendering for only specific pages (i.e. all back sides in a job), Exception Page Programming must be used, which can be tedious and cumbersome. Pure rendering is used for text only option and is not optimized for good IQ for R=G=B pixels. Hence this solution is usually unacceptable for high quality cost-critical customers.
Presented herein is a GCR-based approach to replace the output CMYK to print K only for neutrals, which helps to increase the applicability to multiple source spaces. An example use of this feature is when a user/customer has a desire to print K only for neutrals particularly while honoring the embedded source profiles.